The resection angle in apical surgery: a CBCT assessment

Piezoelectric Device and Dynamic Navigation System Integration for Bone Window-Guided Surgery

INTRODUCTION

This study investigates the feasibility of integrating a piezoelectric device (PIEZO) into a dynamic navigation system (DNS) for bone-window guided surgery. It compares the accuracy and efficiency of PIEZO + DNS to PIEZO + Freehand (FH) procedure for bone-window cutting and root-end resection (RER).

METHODS

Forty-eight mandibular molars of 3D-printed surgical jaw models were divided into two groups: PIEZO + DNS (n = 24) and PIEZO + FH (n = 24). Cone-beam computed tomography scans were taken before and after the procedure. The procedure was virtually planned on X-guide software. The bone-window cutting and RER were conducted with a PIEZO under dynamic navigation in the PIEZO + DNS group and using the dental operating microscope in the PIEZO + FH group. The 2D- and 3D-accuracy deviations and angular deflection were measured for the bone window cut. The root length resected and resection angle were calculated. The bone window cut, RER, total operating time, and number of mishaps were recorded.

RESULTS

PIEZO + DNS was more accurate than PIEZO + FH for bone-window cutting, showing fewer 2D and 3D deviations and less angular deflection (P < .05). The resection angle was lower in the PIEZO + DNS (P < .05). The bone-window cut and total operating time were significantly reduced using a DNS (P < .05). There was no difference in the number of mishaps (P > .05).

CONCLUSIONS

Within the limitations of this in vitro study, the integration of a PIEZO into a DNS is feasible for bone-window guided surgery. The DNS improved the accuracy and efficiency of bone-window cutting.

Clinical Outcome and Predictors of Endodontic Microsurgery Using Cone-beam Computed Tomography: A Retrospective Cohort Study

INTRODUCTION

The aim of this retrospective cohort study was to evaluate the clinical outcomes and identify the prognostic factors of endodontic microsurgery based on cone-beam computed tomographic (CBCT) scans.

METHODS

Patients who underwent endodontic microsurgery in teeth with asymptomatic apical periodontitis were included. The clinical outcomes were determined based on clinical and radiographic examinations after surgery 12-48 months. Radiographic healing was assessed on CBCT images by using the modified PENN 3-dimensional criteria and classified into 4 categories: complete, limited, uncertain, and unsatisfactory healing. Multivariate logistic regression was performed to detect outcome risk factors.

RESULTS

Of the 204 teeth in 173 invited patients, 148 teeth of 126 patients were examined at review. On CBCT images, 88 teeth (59.5%) showed complete healing, and 42 (28.4%) teeth showed limited healing. All these 130 teeth were asymptomatic and achieved a clinical success rate of 87.8%. Uncertain healing was observed in 9 teeth, one of which was symptomatic. The remaining 9 teeth were unsatisfactory healing on CBCT scans, including 6 teeth with clinical symptoms and 3 free. Lesion type and root-end filling quality were significant outcome predictors (P < .05). The risk of treatment failure for teeth with combined endodontic-periodontal lesions was 8.6 times higher than that for teeth with isolated endodontic lesions. Adequate root-end filling quality improved the probability of success by 5.3 times.

CONCLUSIONS

Based on CBCT data, an adequate performed endodontic microsurgery could have predictable success in teeth without periodontal involvement.

Treatment-Related Factors Affecting the Success of Endodontic Microsurgery and the Influence of GTR on Radiographic Healing-A Cone-Beam Computed Tomography Study

The primary objective of this retrospective study was to assess the correlation between treatment-related factors (resection angle, depth of retrograde filling, length of resected root and use of guided tissue regeneration-GTR) evaluated using cone-beam computed tomography (CBCT) scans and the treatment outcomes of endodontic microsurgery (EMS). The secondary purpose of this research was to evaluate the influence of the GTR technique on the radiographic healing state, taking into account the initial parameters of periapical lesions. In 161 cases, the local factors (volume of a lesion, bone destruction pattern, presence/absence of cortical bone destruction) were measured using preoperative CBCT images before undergoing EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure (based on radiographic and clinical criteria). Using postoperative CBCT, treatment-related factors (resection angle, depth of retrograde filling, and length of resected root) were measured. Additionally, the status of radiographic healing was evaluated (in accordance with modified PENN 3D criteria). Eighteen cases (11.18%) were classified as failures, and 143 were classified as successes (88.82%). Univariate analysis showed that there was no statistically significant influence of treatment-related factors on the healing outcome of EMS. An exact Fischer's test showed the significant impact of GTR on radiographic healing (P < 0.001) in apical lesions (P < 0.001), lesions with a volume between 100 mm3 and 450 mm3 (P < 0.009) and over 450 mm3 (P < 0.001), lesions with the destruction of one plate (P < 0.001), and lesions with the destruction of two plates (through and through) (P = 0.022). The use of GTR in apical lesions, lesions with volumes over 100 mm3, and lesions with the destruction of at least one plate is significantly associated with better radiographic healing.

Augmented Reality and 3-Dimensional Dynamic Navigation System Integration for Osteotomy and Root-end Resection

INTRODUCTION

Augmented reality (AR) superimposes high-definition computer-generated virtual content onto the existing environment, providing users with an enhanced perception of reality. This study investigates the feasibility of integrating an AR head-mounted device into a 3-dimensional dynamic navigation system (3D-DNS) for osteotomy and root-end resection (RER). It compares the accuracy and efficiency of AR + 3D-DNS to 3D-DNS for osteotomy and RER.

METHODS

Seventy-two tooth roots of 3D-printed surgical jaw models were divided into two groups: AR + 3D-DNS (n = 36) and 3D-DNS (n = 36). Cone-beam computed tomography scans were taken pre and postoperatively. The osteotomy and RER were virtually planned on X-guide software and delivered under 3D-DNS guidance. For the AR + 3D-DNS group, an AR head-mounted device (Microsoft HoloLens 2) was integrated into the 3D-DNS. The 2D- and 3D-deviations were calculated. The osteotomy and RER time and the number of procedural mishaps were recorded.

RESULTS

Osteotomy and RER were completed in all samples (72/72). AR + 3D-DNS was more accurate than 3D-DNS, showing lower 2D- and 3D-deviation values (P < .05). The AR + 3D-DNS was more efficient in time than 3D-DNS (P < .05). There was no significant difference in the number of mishaps (P > .05).

CONCLUSIONS

Within the limitations of this in vitro study, the integration of an AR head-mounted device to 3D-DNS is feasible for osteotomy and RER. AR improved the accuracy and time efficiency of 3D-DNS in osteotomy and RER. Head-mounted AR has the potential to be safely and reliably integrated into 3D-DNS for endodontic microsurgery.

Accuracy and Efficiency of Endodontic Microsurgery Assisted by Dynamic Navigation Based on Two Different Registration Methods: An In Vitro Study

INTRODUCTION

This study aimed to compare the accuracy and efficiency of dynamic navigation-assisted endodontic microsurgery (DN-EMS) using two different registration methods.

METHODS

Three-dimensional-printed jaw models, including 40 teeth, were divided into two groups (n = 20). Cone-beam computed tomography images of all teeth were scanned under the same exposing parameters. An endodontic dynamic navigation system (DHC-ENDO1) was used to plan the drilling paths. Dynamic navigation-assisted endodontic microsurgery (DN-EMS) was performed using either U-shaped tube (UT) or tooth cusp (TC) registration method. The accuracy was determined by platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. The registration efficiency was defined as the time required to complete the registration procedure. Osteotomy volume of each resection was calculated by Mimics 21.0. Statistical analyses were performed using IBM SPSS Statistics 24.0. Comparisons between groups were performed using the independent sample t test or Mann-Whitney U test. P < .05 was adopted as significant difference.

RESULTS

The UT group was significantly more accurate in terms of mean platform deviation, end deviation, angular deviation, and resection angle (P < .05). Resection length deviation did not differ significantly between the registration groups. The UT group was significantly more efficient than the TC group (P < .05). No significant differences were found in the osteotomy volumes between the two groups.

CONCLUSIONS

In the model-based surgical simulation comparison, DN-EMS based on UT registration is more accurate and efficient than the TC method but requires an additional registration device. TC technique may be a reasonable alternative to UT registration in certain clinical tasks.

Comparison of a Novel Static Computer-aided Surgical and Freehand Techniques for Osteotomy and Root-end Resection

INTRODUCTION

This study compared the accuracy and efficiency of a novel static computer-aided surgical technique using a 3-dimensional (3D)-printed surgical guide (3D-SG) with a fully guided drill protocol (3D-SG FG) to the freehand (FH) osteotomy and root-end resection (RER).

METHODS

Forty-six roots from 2 cadaver heads were divided into 2 groups: 3D-SG FG (n = 23) and FH (n = 23). Cone-beam computed tomographic scans were taken preoperatively and postoperatively. The endodontic microsurgery was planned in Blue Sky Bio software, and the 3D-SG was designed and 3D printed. The osteotomy and RER were conducted using a guided twist drill diameter of 2 mm and an ascending tapered drill with diameters of 2.8/3.2, 3.2/3.6, 3.8/4.2, and 4.2 mm with respective guided drill guides. Two-dimensional and three-dimensional virtual deviations and angular deflection were calculated. Linear osteotomy measures and root resection angle were obtained. The osteotomy and RER time and the number of mishaps were recorded.

RESULTS

Two-dimensional and three-dimensional accuracy deviations and angular deflection were lower in the 3D-SG FG protocol than in the FH technique (P < .05). The height, length, and depth of the osteotomy and root resection angle were less in the 3D-SG FG protocol than in the FH technique (P < .05). The osteotomy and RER time with the 3D-SG FG protocol were less than the FH method (P < .05).

CONCLUSIONS

Within the limitations of this cadaver-based study using denuded maxillary and mandibular jaws, 3D-SG FG protocol showed higher accuracy than FH osteotomy and RER. Moreover, the 3D-SG FG drill protocol significantly reduced the surgical time.

Outcomes of endodontic microsurgery using different calcium silicate-based retrograde filling materials: a cohort retrospective cone-beam computed tomographic analysis

PURPOSE

To evaluate the outcomes of endodontic microsurgery (EMS) using mineral trioxide aggregate (MTA; Dentsply Sirona, Charlotte, NC, USA), EndoSequence root repair material (RRM putty; Brasseler, Savannah, GA), and injectable Bioceramic (BC) sealer (Brasseler USA) followed by the application of RRM putty (lid technique) as root-end filling materials.

METHODS

One hundred and ten patients who underwent EMS between 2016 and 2020 at King Abdulaziz University Dental Hospital were recruited for clinical and radiographic follow-up after a minimum of 1 year. Radiographic assessment was performed using periapical radiographs (PAs) and cone-beam computed tomography (CBCT). Volumetric analysis of periapical radiolucencies (PARLs) was performed using Amira software.

RESULTS

Seventy-nine patients (103 teeth: MTA group, n = 28; RRM putty, n = 41; lid technique, n = 34), attended the follow-up visit, with an average follow-up period of 24 months (recall rate = 74.5%). Of the 103 teeth, 40 were anteriors, 24 were premolars, and 39 were molars. All three groups of retrograde filling materials (MTA, RRM putty, and lid technique) showed high success rates on both PA (85.7, 85.4, 94.1%, respectively) and CBCT imaging (67.9, 75.6, 88.2%, respectively), without any significant difference among the success rates of different materials. Overall, a slight agreement was noted between the PA and CBCT outcomes, with a statistically significant difference (P = 0.029). None of the patient-, tooth-, or treatment-related factors significantly influenced the outcomes of EMS. Adequate density of root canal filling material was significantly associated with a high percentage of completely healed cases on CBCT (P = 0.044). PARL volumes were reduced significantly over 1-4 years follow-up after EMS (P < 0.001) CONCLUSIONS: EMS showed high success rates on both PA and CBCT when MTA, RRM putty or lid technique were used as retrograde filling materials. CBCT imaging is more precise than PA in detecting the healing outcomes of EMS.

REAL-TIME 3D IMAGE-GUIDED NAVIGATION SYSTEM IN ENDODONTIC MICROSURGERY - A CADAVER STUDY

INTRODUCTION

This study evaluated the accuracy and efficiency of 3D Dynamic Navigation System (3D-DNS) to perform minimally invasive osteotomy (MIO) and root-end resection (RER) in endodontic microsurgery (EMS) and investigated the viability of root-end cavity preparation (RECP) and fill (REF) in MIO.

METHODS

We divided 48 tooth roots in cadaver heads into two groups: 3D-DNS (n = 24) and freehand (n = 24). Cone beam computed tomography (CBCT) scans were taken before and after surgery. First, we verified virtual 3D-DNS accuracy using three outcome measures: 2D and 3D virtual deviations and angular deflection (AD). Second, we investigated 3D-DNS's accuracy for performing MIO in two outcome measures: Osteotomy size and volume. Third, we determined the 3D-DNS accuracy for RER in three outcomes: Resected root length, root length after resection, and resection angle. We investigated the viability of RECP and REF and measured REF depth and volume, as well, recording procedural times and number of mishaps.

RESULTS

2D and 3D virtual deviations and AD were lower in the 3D-DNS than FH (p<.05). Osteotomy height, length, and volume were all reduced when using 3D-DNS (p < .05). The resection angle was lower for the 3D-DNS (p<.05). RECP and REF were completed in 100% of the roots. The REF depth achieved was ∼ 3mm. Osteotomy time, RER time, and total procedure time were all significantly shortened using 3D-DNS (p < .05).

CONCLUSIONS

3D-DNS enabled our surgeon to perform accurate and efficient EMS with minimally invasive osteotomy and RER. The surgeon was also able to conduct RECP with adequate REF in minimally invasive osteotomy performed using 3D-DNS guidance.

Long-Term Prognosis of Endodontic Microsurgery-A Systematic Review and Meta-Analysis

Background and objectives: The long-term outcome of endodontic microsurgery (EMS) performed on root-filled teeth affected by post-treatment apical periodontitis (AP) has been a matter of debate, re-launched by the introduction of novel root-end filling materials which have been proven to improve the short-term outcome of EMS. The purpose of this systematic review and meta-analysis is to evaluate the clinical and radiographic long-term outcome of endodontic microsurgery in teeth diagnosed with secondary AP through radiographic evaluation. Materials and Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion and exclusion criteria were defined a priori to select the best longitudinal evidence. Only randomized clinical trials (RCT) and prospective clinical studies (PCS), with a follow-up ≥ 2-year, and exhibiting well-established clinical and radiographic outcome criteria, were selected. Results: A total of 573 articles were obtained, from which 10 fulfill inclusion criteria: 6 PCS and 4 RCT. Meta-analysis showed a pooled proportion of success rate of 91.3%, from an overall amount of 453 treated teeth included in RCT; from overall 839 included teeth in PCS, a pooled success rate of 78.4% was observed, with the follow-up time ranging from 2 to 13-years. Survival rate outcomes varied from 79 to 100% for the same follow-up period. Five prognostic factors with influence on the outcome were disclosed: smoking habits, tooth location and type, absence/presence of dentinal defects, interproximal bone level, and root-end filling material. Conclusions: High success rates and predictable results can be expected when EMS is performed by trained endodontists, allowing good prognosis and preservation of teeth affected by secondary AP.

The Effect of Resection Angle on Stress Distribution after Root-End Surgery

Introduction:

This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application.

Methods and Materials:

A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45^º occlusal load of 200 N/cm² on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS).

Results:

MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group.

Conclusion:

Apicectomy at 90^º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45^° could be a good choice for clinicians.